Perforating gun for oil wells



June 4, 1940. F. c. KNlss 2,203,265

PERFORATING GUN FOR OIL WELLS Filed May 22, 1937 3 Sheets-Sheet 2 j 70' 4 -T rf/ /5 7U J f z" da C'X iss.

June 4, 1940. F. c. KNlss 2,203,265

PERFGRATING GUN FOR OIL WELLS Filed May 22, 1957 5 Sheets-Sheet 5 Patented June 4, 1940 ention relates to an improved perfos, such as oil wells, and on is to provide a gun to a well to a desired then discharged so that h the gun is loaded will be red and into walls of the hatter the portions of rating gun for use in well one object of the inventi which may be lowered 5 position therein bullets with whic through the well casing well and thus serve to s the Walls which have become clogged and cause the oil to again flow free Another object of the 1 the gun that it may be freely low casing of the well and then manipulated by vertical movement which will cause gripping eleght into engagement with the then actuated to explode the gun and discharge nvention is to so form ered in the ments to be brou casing and mechanism cartridges carried by bullets through the well casing and into walls the invention is to so cononnected with Another object of struct the gun that it may be c the lower end of a string of tools ordinari n oil well when it is in use.

thus be see quired for lowering the discharging the same an equipment will be accomplished.

The invention is illustrated in the accompanying drawings, wherein is a longitud ed gun showing the same as being lowered into a well,

milar to Figure 1 and illusn that no special apparatus is regun into the well and d, therefore, a saving in inal sectional view through the improv it will appear while e 2 is a view si trating the manner in which the gun is actuated in order to discharge the gun,

Figure '3 is another and 2 and showing ano portions of the gun during Figure 4 is an enlarged fragme view taken vertically th Figure 5 is a section through the gun along Figure 6 is a sec scale taken through the gun an ingalong the line 6--6 of Figure '1 is a vie and partially in ver a-gun of a modifled construction,

Figure 8 is an enlarged sectional vie 4tion of the gun illustr Figure 9 is a view si ing a modified c Figure 10 is a taken longitudinali construction where ilar to Figures 1 ther position occupied by ring thereof,

ntary sectional rough the gun,

l view taken transversely the line 5-5 of Figure 4, tional view upon an d the Well castially in side elevation tical section and illustrating ated in Figure 7,

mlar to Figure 8 illustratonstruction, and

fragmentary sectional view y through a gun of a modified in bullets are discharged from UNITED STATES PATENT CFFICE PERFORATING GUN FOR OIL WELLS Frank C. Kniss, Eldorado, Ark. Application May 22, 1937, Serial No. 144,276

opposite sides of the gun instead of from only one side thereof.

This improved gun is intended to be connected with the lower end of a string of well tools, one of which is indicated in general by the numeral I, and it is to be understood that the string of well tools will be of a conventional construction and may include a jar which is also of a conventional construction and operated in the usual manner by reciprocating the string of tools ver- 1D tically in the well. This string of tools and the gun will be forced downwardly through the well casing 2 which is of the usual tubular formation and consists of the usual series of pipe sections connected one with another. 15

The body portion 3 of the gun is in the form of an elongated metal bar having a neck 4 at its upper end carrying a head 5 from which projects a threaded shank 6 adapted to be secured into the lower end of the lowermost one of the 20 string of tools. The head 5 constitutes a wrenchengaging member by means of which the shank 6`may be screwed tightly into the well tool. This metal bar or body of the gun will be of such diameter that it will slide freely through the 25 well casing 2, and at one side the body is formed with a longitudinally extending groove or recess 1 which is of an even width throughout its length and has its upper portion of an even depth and its lower portion 1Bh of gradually in- 30 creasing depth and formed at its inner wall with side extensions or recesses 1b. A groove or recess 1c of less width than the inner wall of the groove or channel 1 is formed along the upper portion of the channel or there may be provided a series 35 of these grooves 1c in vertical spaced relation to each other.

Threaded sockets 8 which may be of any number desired are formed transversely of the body from one side thereof, and into these sock- 40 ets are screw barrels 9 for receiving cartridges I0, it being understood that, in order to apply the cartridges, the barrels must be unscrewed, the cartridges thrust into the barrels from inner ends thereof, and the valves then again screwed 45 into the socket. The cartridges will thus be supported, as shown in Figures 1, 2 and 4, and each have its primer disposed in position for engagement by a firing pin II. The ring pins are slidably received through openings I2 extending be- 50 tween the sockets and the inner wall of the upper portion of the groove or channel 1 and are engaged by the inner edge face of a ring bar I3 which is slidably received in the upper portion of the channel 1 and held in engagement with 55 an abutment bar I4 by leaf springs I5. These springs I5 extend longitudinally of the channel and each has one end portion secured in one of the grooi. es or recesses IC and its free'end portion bearing against the inner edge face of the firing bar. Confronting faces of the bar I4 and the firing bar I3 are formed with teeth I6 and I'I, and from an inspection of Figure 4, it will be readily understood that, when pressure is applied to the lower end of the stem or shank I8 at the bottom of the firing bar to force this bar upwardly in the channel 1, a cam action will take place between the sloping edge faces of the teeth I6 and II to shift the firing bar toward the inner wall of the channel and thus apply pressure to the ring pin which will force the firing pin into the primers of the cartridges and thus explode the cartridges. When the cartridges explode, the bullets will be forced from the shells and through the well casing into the walls of the well and the walls of the well will be shattered to such an extent that flow of oil which has been stopped by clogging will be restored.

A block I9 is slidably received in the lower portion Ia of the slot 'l and extends transversely therein, as shown in Figures 1, 2 and 3. The block tapers towards its upper end and along its inner side edge is formed with side extensions or ribs 20 which engage in the grooves Ib and prevent this block from dropping through the open side of the slot when the device is not in use. The outer side edge of the block is beveled from opposite side faces of the block to form a cutting edge 2I which intersects the lower edge of the block to form a tooth 22 adapted to penetrate the well casing 2, as shown in Figure 3 and in Figure 6. From an inspection of Figures l, 2 and 3, it will be seen that, when the block is in a lowered position, it will be entirely housed in the lower portion of the slot "Ia, whereas, when it is shifted upwardly, it will be caused to project from the open side of the slot and have biting engagement with the well casing, after which it will be forced through the well casing as the body 3 of the gun moves downwardly and it will eventually make contact with the lower end of the shank I8 to shift the firing bar I3 upwardly and cause the pins or plungers II to be forced into engagement with the primers of the cartridges and explode'the cartridges. A barrier 23 closes the lower end of the slot and through this barrier is formed an opening 24 to slidably receive a rod 25. This rod constitutes means for moving the block I9 from the position shown in full lines in Figure 1 to that indicated by dotted lines, and in addition also serves as a hanger or carrier for a set of springs 26. 'I'hese springs are formed from strips of resilient sheet metal and each has a vertically extending portion and upper and lower arms extending therefrom toward the rod 25. The ends of the arms are disposed in overlapping relation to each other and formed with alined openings through which the rod passes. The arms are of such a length that, when the device is in use and thrust into a well casing, the vertically extending portions of the springs will have frictional binding engagement with the walls of the casing. By this arrangement the gun may be lowered into a well until it has reached a predetermined depth, at which time the string of tools will be drawn upwardly a sufficient distance to cause the rod to be drawn upwardly from the position shown in Figure 1 to that shown in Figure 2, and these springs will have tight binding engagement with Walls of the well casing and also have tight binding engagement with the rod. The string of tools and the gun may be again lowered and, when the head at the upper end of the rod engages the lower edge face of the block I9, the block will be shifted upwardly to the position indicated by dotted lines in Figure 1. At this point the tooth 22 of the block will be brought into biting engagement with the casing I and the block will be held against further downward movement in the well casing. The string of tools and the gun may then be reciprocated vertically and the cam action which takes place between the block and the diagonally extending inner edge wall of the slot will cause the block to be gradually shifted radially of the gun and the well casing and the tooth 22 and the sharpened outer side edge of the block forced through the wall of the well casing. The weight of the string of well tools and the gun may be depended upon to forceV the block through the'well casing to the position shown in Figure 3 or a jar of a conventional construction can be provided between the gun and the lower one of the string of well tools. It will be understood that the springs will be carried downwardly in the well with the gun during movement of the block to the position shown in Figure 3. Further reciprocating movement of the string oi' tools will cause the lower end of the shank I8 to engage the upper end of the block and the ring bar I3 will then be forced upwardly and the cam action which takes place between the bar and the cam bar I4 will move the firing bar transversely and force the firing pins into engagement with the primers of the cartridges. The cartridges will then be exploded and the bullets discharged through the well casing and into the wall of the well to break up portions of the wall of the well and thus cause the well to flow freely.

Instead of discharging bullets from only one side of the gun, they may be discharged from opposite sides thereof, in which case a construction such as shown in Figure l will be employed. Referring to this gure, it will be seen that the upper portion of the' slot I will extend through the body of the gun axially thereof and barrels 9 to receive the cartridges I0 will be mounted in diametrically opposed side portions of the body. The ring pins 2'I which are slidably mounted in the pocket 28 extend into the slot 'I for engagement by the firing bar 29. These bars 29 are yieldably held against opposite side edges of a bar 30 by springs 3I which correspond to the springs I and contacting portions of the bar 30 and the firing bars 29 are formed with a tooth or serrated portion defining cooperating cam members 32 and 33. The lower end of the actuating bar 30 will extend into the widened lower portion 'Ia of the slot 'I and terminate in a, shank corresponding to the shank I8 so that, when the device is in use and the lower end of the actuating bar is engaged by the block I9, the actuating bar will be shifted upwardly and the firing bars shifted transversely to force the ring pins into engagement with the primers of the cartridges and explode .the cartridges. It will be obvious that additionalsets of cartridges may be provided for the gun.

In Figures 7, 8 and 9, there has been shown another modified construction wherein the block I9 is eliminated and the ring bar i3 is slidably mountedin a slot 34 corresponding to the slot I but having its -lower end communicating with a pocket 35 formed in the lower portion of the body 3 instead of terminating in a deepened lower portion corresponding to the portion 1B of the slot previously shown and described. The lower end of the pocket 35 is closed by a plug 38 having an axially extending bore 31 through which slidably passes a rod or plunger 38. 'Pins 38 are employed to secure the plugs in the lower end of the pocket or any other desired means may be employed. The upper end portion of the bore 31 is enlarged to form a socket 40 having threaded walls and the upper end of the rod 38 is formed with an enlarged threaded neck 4l carrying a disk-like head 42 and adapted to be screwed into the socket 48. It will thus be seen that the rod may be held stationaryduring lowering of the device into a well and that after it has been lowered to the desired position the string of tools and the gun turned in a direction to unscrew the neck from the socket. Instead of having the plug formed with a bore terminating in a threaded socket, it may be formed with a bore 43 of an even diameter throughout its length, as shown in Figure 9, in which case the rod 38 will be provided with a head-like disk 44 at its upper end corresponding to the head 42, but the threaded neck 4| will be omitted. When the construction shown in Figure 9 is used in place of that shown in Figure 8, a pin 45 is passed through alined openings formed in the shaft or rod and the lower portion of the plug, and this pin will be formed of such material that, while it will prevent sliding movement of the rod through the plug during lowering of the gun into a well, reciprocating movement of the gun after the gun has been lowered to the desired position will cause the pin to be sheared and thus permit movement of the gun and the rod or plunger relative to each other.

At its lower end the rod or plunger 38 carries a block 46 which is of an inverted frusto-conical formation and constitutes a cam or wedge, and from the lower end of the wedge 46 extends a hollow guide 41 which is formed with longitudinally extending slots 48 in its opposed side portion. The head 4 9 at the lower end of the guide i1 is formed with a central opening 58 through which extends a rod corresponding to the rod 25, and about this rod are disposed springs 52 corresponding to the springs 26. The upper end of the rod which is within the guide carries a head 53 of a diameter to be slidably received in the guide and from opposite sides of this head extend ears or lugs 54 which project outwardly through the slot 48 and are pivotally connected to lower ends of links 55. The links 55 extend longitudinally of the guide and at their upper ends are pivoted to ears 56 at the lower ends of dogs 51 which along their inner portions are formed with side ribs 58 engaged in undercut grooves 59 formed in opposite side portions of the wedge 46. From an inspection of Figure 7, it will be readily understood that after the gun has been lowered into a well and then drawn upwardly a short distance to expand the springs 52 and draw the rod 5I upwardly the gun may then be lowered and as it moves downwardly the guide 41 will slide downwardly along the upper portion of the rod with the head 53 moving upwardly in the guide and the wedge will cause the block or dog 51 to be moved radially in the well casing and the teeth formed upon the outer edge faces of the dogs will be brought into gripping engagement with the walls of the well casing. The gun may then be turned to unscrew the neck 4l from the socket 40 or a jaw carried by the string of tools actuated to shear the pin 85 and the body of the gun may then slide downwardly along the rod 38 to bring the head 42 into engagement with the lower end of the shank I8 of the tiring bar I3 and effect discharge of the cartridges.

Having thus described the invention, what is claimed as new is:

1. A well-shooting device comprising a body adapted to be lowered into a well casing, the body being formed with a longitudinally extending slot and with transverse pockets, barrels in said pockets for receiving cartridges equipped with projectiles, firing pins for the cartridges carried by the body and extending into said slot, a :tiring bar mounted in said slot, said bar being slidable longitudinally in said slot and shiftable transversely therein towards and away from said pins, means for shifting the bar towards the pins and moving the pins in a direction to discharge the cartridges when the bar is moved longitudinally in one direction and cause the projectiles to pern forate the casing, and means for sliding the bar in the said direction adapted to be actuated by reciprocating movement of the body in a well.

2. A well-shooting device comprising a body adapted to be lowered into a well casing, the body being formed with a longitudinally extending slot and at one side of the slot being formed with transverse pockets and reduced passages leading from inner ends of the pockets to said slot, means in said pockets for carrying cartridges equipped with projectiles, iiring pins for the cartridges slidably received through the passages and projecting into the slot, a firing bar slidable longitudinally in said slot, a guide bar in said slot, the ring bar and the guide bar being formed with cooperating cam portions for shifting the firing bar towards the pins and effecting discharge of cartridges when the firing bar is slid longitudinally in one direction whereby the projectiles will penetrate said casing, springs in the slot for urging the firing bar toward inoperative position, and means carried by said body for effecting movement of the firing bar to operative position during reciprocation of the body in a well.

3. A well-shooting device comprising a body adapted to be lowered in a well casing, the body being formed with a longitudinally .extending slot and a portion of the slot being formed with a diagonally extending inner wall, means for mounting in the body transversely thereof cartridges equipped with projectiles, firing pins for the cartridges slidably carried by the body and extending into the slot, a firing bar slidable longitudinally in said slot, a cam member for shifting the bar towards the pins and moving the pins in a direction to re cartridges when the bar is slid upwardly in the slot and cause the projectiles to penetrate said casing, a block slidable longitudinally in the portion of the slot .baring the diagonally extending inner wall and normally disposed at the lower end of the slot and entirely housed in the slot, means carried by the body for initially moving the block upwardly .in the slot whereby the inclined wall will force the block out of the slot and into biting engagement with a well casing and hold further downward movement of the block with the body, further downward movement of the body serving to bring the block into engagement with the lower end of the ilring bar and shift the bar upwardly to effect discharge of the cartridges.

4. A well-shooting gun comprising a body to be reciprooated within a well casing and having a longitudinally extending slot open ai side of the body and having a lower portion formed with a diagonally extending inner wall,

a barrier for the lower end of the slot, means for mounting in the body cartridges equipped with projectiles, firing pins extending into the upper portion of the slot through the inner wall thereof, a firing bar slidable longitudinally in the upper portion of the slot and shiftable transversely therein toward the firing pins whereby said iir ing pins will discharge the cartridges so that the projectiles will penetrate the casing, a guide bar mounted in the slot and having cam meinbers for shifting the firing bar towards the pin when the ring bar is slid upwardly, a block slidable longitudinally of the body in the lower portion of the slot, the block being housed in the slot when at the lower end thereof and being gradually movable outwardly through the open side of the block as it is moved toward the upper end of the tapered lower portion of the block, said block being formed at its outer end with a toothfor biting into a well casing and having a sharpened edge for cutting through the well casing as the block is moved toward the up- Per G Ild of the slot into position for engagement with the lower end of the ring bar to effect upward movement of the firing bar, a rod extending through said barrier and depending from the lower end of said body, and springs loosely carried by the rod and extending laterally therefrom for engagement with walls of a well casing whereby the rod may be drawn upwardly through the springs as the body is drawn upwardly and maintained in the elevated position to engage the block and shift the block upwardly into biting engagement with the well casing as the body is again moved downwardly.

5. A weil-shooting device comprising a body formed with a longitudinally extending slot, means for mounting in the body transversely vthereof cartridges equipped with projectiles, firing pins `for cartridges carried by the body and extending into 'the slot, a ring bar slidable longitudinally in the slot, said body having its lower portion formed with a pocket and said bar having its lower portion extending into the pocket, .a closure for the lower end of the pocket, a plunger slidable vertically through the closure and having a head at its upper end disposed within the pocket, means for releasably holding the plunger against movement relative to the body, the plunger when released being movable relative to the body whereby the bodyvmay be shifted downwardly along the plunger to move the head of the plunger into engagement with the lower end of the ring bar and shift the bar upwardly into position to force the ring pin transversely of the body into position to dis charge cartridges and expel the projectiles therefrom, and means for engaging walls-of ,a well casing and supporting the plunger inastationary position in the-well casing. y

6. A well-shooting device comprising a. body, means for mounting in a body transversely thereof cartridges equipped with projectiles, a firing bar slidable longitudinally of the bodyr and having its lower end extendingvinto a pocket formed in the body, a plunger slidably carried by the body with its upper end extending int'o the body and formed with a head for engaging the rod and shifting the rod upwardly when the plunger is held stationary, a wedge carried by said plunger and tapered downwardly, a cylindrical gui-de extending downwardly from said wedge and formed with side slots, a rod slidably carried by said guide with its upper end portion extending into the guide and provided with ears extending outwardly through`the slots, gripping dogs slidably carried by said wedge, links connecting the dogs with said ears, and springs loosely carried by said rod and extending radially therefrom for engaging walls of a well casing and holding the rod stationary.

7. In a well lshooting gun, a body to be reciprocated in a well casing and having a slot, cartridge supporting means in the body, a cartridge carried in the cartridge supporting means, said cartridge having a projectile, a. firing bar movable in the slot, a ring pin for the cartridge, said firing bar being engageable with the firing pin for discharging the cartridge and perforating the well casing with the projectile, a block movable in the slot and having a tooth for biting into a well casing, a rod slidable through the lower end of the body and being engageable with the block for urging said block into engagement with the firing bar for discharging the cartridge and causing the tooth to bite into the well casing upon reciprocation of the body.

8. In a device of the class described, a body adapted to be lowered into a well casing, said body being provided with means for holding a cartridge having a projectile therein, a ring bar, Va ring pin engageable by the firing bar for engaging the cartridge and discharging said cartridge so that the projectile will penetrate a well casing, said firing bar being movable, a block movable on the body and having a tooth for biting into a Well casing, a rod slidably connected with the body and engageable with the block for urging the block into engagement with the firing bar for discharging the cartridges and causing the tooth to bite into the well casing upon reciprocation of the body.

FRANK C. KNISS. 

